How much is your customer support time worth? These people are responsible for your repeat business and it makes sense to make their job as clear and as simple as possible. Give them clear guidelines and the tools to do their job properly.
If they are still using email to interact with your customers, you need to reconsider this. Email isn’t the most reliable of communication methods, delivery isn’t guaranteed and you open your support staff to security problems.
A recent survey of ‘trouble ticket’ systems left me underwhelmed. I did trial one that required tomcat to be installed on the server. The security implications left me uneasy (fears which were subsequently confirmed) and the system simply didn’t provide enough functionality. Your support system should integrate with your orders system, showing the customer full order history and previous interactions with your staff. It should give clear indications of levels of replacement stock, should that be needed, without the support staff having to exit and open half a dozen different screens.
In the end, I wrote one from scratch. It took me about 2 weeks. It was refined once in production, but it functioned from the start.
If this is something that you think I could help with, get in touch.